1. Technical Field
The present disclosure relates to a display device and electronic apparatus capable of detecting an externally approaching object, and more particularly, to a display device with a touch detection function and an electronic apparatus capable of detecting an externally approaching object based on a change in electrostatic capacitance.
2. Description of the Related Art
Recently, much attention has been paid to a touch detection device, which is called touch panel, capable of detecting an externally approaching object. The touch panel is used for a display device with a touch detection function in which the touch detection device is attached onto or integrated with display device such as liquid crystal display device. The display device with a touch detection function enable the touch panel to be used for information input as substitutes for conventional mechanical buttons by displaying various button images on the display device. The display device with a touch detection function having such touch panel requires no input devices such as a keyboard, a mouse, and a keypad, thereby tending to be widely used for a portable information terminal such as a portable phone in addition to a computer.
There are several touch detection methods such as optical method, resistive method, and electrostatic capacitance method used for the touch detection device. The touch detection device using the electrostatic capacitance method has relatively simple structures and can achieve low power consumption device when used in the portable information terminal, for example. For example, Japanese Patent Application Laid-open Publication No. 2012-221485 (JP-A-2012-221485) discloses an electrostatic capacitive touch panel.
In the display device with a touch detection function, which integrate therein a display function and a touch detection function, an operation for detecting a touch may influence the display, for example. The display panel with a touch detection function (display device with a touch detection function) disclosed in JP-A-2012-221485 can reduce the influence on the display due to the touch detection. The display panel with a touch detection function disclosed in JP-A-2012-221485 includes a drive unit that selectively applies a direct-current drive signal VcomDC or an alternating-current drive signal VcomAC to a drive electrode. In the display panel with a touch detection function, the drive signal is applied to the drive electrode and a signal according to the drive signal is output from a touch detection electrode while a display element is display-driven. Two wiring for supplying the direct-current drive signal VcomDC and the alternating-current drive signal VcomAC to the drive electrode thus need to be routed in a frame area.
The display panel with a touch detection function disclosed in JP-A-2012-221485 includes a selection switch that selectively supplies the direct-current drive signal VcomDC and the alternating-current drive signal VcomAC to the drive electrode through the two wiring. In the display panel with a touch detection function disclosed in JP-A-2012-221485, the interconnection resistance in the selection switch may influence a time constant of a waveform of the drive signal. The selection switch, thus, needs to be enlarged in order to reduce the interconnection resistance thereof. The increase in the size of the selection switch may enlarge the frame area, which does not contribute to function as a display area.
For the foregoing reasons, there is a need for a display device with a touch detection function and an electronic apparatus capable of reducing the interconnection resistance of the selection switch that selects a drive electrode to which the drive signal is applied and capable of reducing the frame in size.